<template>
  <s-layout
    navbar="normal"
    :leftWidth="0"
    :rightWidth="0"
    tools="search"
    :defaultSearch="state.keyword"
    @search="onSearch"
  >
    <!-- 筛选 -->
    <su-sticky bgColor="#fff">
      <view class="ss-flex">
        <view class="ss-flex-1">
          <su-tabs
            :list="state.tabList"
            :scrollable="false"
            @change="onTabsChange"
            :current="state.currentTab"
          />
        </view>
        <view class="list-icon" @tap="state.iconStatus = !state.iconStatus">
          <text v-if="state.iconStatus" class="sicon-goods-list" />
          <text v-else class="sicon-goods-card" />
        </view>
      </view>
    </su-sticky>

    <!-- 弹窗 -->
    <su-popup
      :show="state.showFilter"
      type="top"
      round="10"
      :space="sys_navBar + 38"
      backgroundColor="#F6F6F6"
      :zIndex="10"
      @close="state.showFilter = false"
    >
      <view class="filter-list-box">
        <view
          class="filter-item"
          v-for="(item, index) in state.tabList[state.currentTab].list"
          :key="item.value"
          :class="[{ 'filter-item-active': index === state.curFilter }]"
          @tap="onFilterItem(index)"
        >
          {{ item.label }}
        </view>
      </view>
    </su-popup>

    <!-- 情况一：单列布局 -->
    <view v-if="state.iconStatus && state.pagination.total > 0" class="goods-list ss-m-t-20">
      <view
        class="ss-p-l-20 ss-p-r-20 ss-m-b-20"
        v-for="item in state.pagination.list"
        :key="item.id"
      >
        <s-goods-column
          class=""
          size="lg"
          :data="item"
          :topRadius="10"
          :bottomRadius="10"
          @click="sheep.$router.go('/pages/goods/index', { id: item.id })"
        />
      </view>
    </view>
    <!-- 情况二：双列布局 -->
    <view
      v-if="!state.iconStatus && state.pagination.total > 0"
      class="ss-flex ss-flex-wrap ss-p-x-20 ss-m-t-20 ss-col-top"
    >
      <view class="goods-list-box">
        <view class="left-list" v-for="item in state.leftGoodsList" :key="item.id">
          <s-goods-column
            class="goods-md-box"
            size="md"
            :data="item"
            :topRadius="10"
            :bottomRadius="10"
            @click="sheep.$router.go('/pages/goods/index', { id: item.id })"
            @getHeight="mountMasonry($event, 'left')"
          >
            <template v-slot:cart>
              <button class="ss-reset-button cart-btn" />
            </template>
          </s-goods-column>
        </view>
      </view>
      <view class="goods-list-box">
        <view class="right-list" v-for="item in state.rightGoodsList" :key="item.id">
          <s-goods-column
            class="goods-md-box"
            size="md"
            :topRadius="10"
            :bottomRadius="10"
            :data="item"
            @click="sheep.$router.go('/pages/goods/index', { id: item.id })"
            @getHeight="mountMasonry($event, 'right')"
          >
            <template v-slot:cart>
              <button class="ss-reset-button cart-btn" />
            </template>
          </s-goods-column>
        </view>
      </view>
    </view>
    <uni-load-more
      v-if="state.pagination.total > 0"
      :status="state.loadStatus"
      :content-text="{
        contentdown: '上拉加载更多',
      }"
      @tap="loadMore"
    />
    <s-empty v-if="state.pagination.total === 0" icon="/static/soldout-empty.png" text="暂无商品" />
  </s-layout>
</template>

<script setup>
import { reactive } from 'vue';
import { onLoad, onReachBottom } from '@dcloudio/uni-app';
import sheep from '@/sheep';
import _ from 'lodash';
import { resetPagination } from '@/sheep/util';
import SpuApi from '@/sheep/api/product/spu';

const sys_navBar = sheep.$platform.navbar;
const emits = defineEmits(['close', 'change']);

const state = reactive({
  pagination: {
    list: [],
    total: 0,
    pageNo: 1,
    pageSize: 6,
  },
  currentSort: undefined,
  currentOrder: undefined,
  currentTab: 0, // 当前选中的 tab
  curFilter: 0, // 当前选中的 list 筛选项
  showFilter: false,
  iconStatus: false, // true - 单列布局；false - 双列布局
  keyword: '',
  categoryId: 0,
  tabList: [
    {
      name: '综合推荐',
      list: [
        {
          label: '综合推荐',
        },
        {
          label: '价格升序',
          sort: 'price',
          order: true,
        },
        {
          label: '价格降序',
          sort: 'price',
          order: false,
        },
      ],
    },
    {
      name: '销量',
      sort: 'salesCount',
      order: false,
    },
    {
      name: '新品优先',
      value: 'createTime',
      order: false,
    },
  ],
  loadStatus: '',
  leftGoodsList: [], // 双列布局 - 左侧商品
  rightGoodsList: [], // 双列布局 - 右侧商品
});

// 加载瀑布流
let count = 0;
let leftHeight = 0;
let rightHeight = 0;

// 处理双列布局 leftGoodsList + rightGoodsList
function mountMasonry(height = 0, where = 'left') {
  if (!state.pagination.list[count]) {
    return;
  }

  if (where === 'left') {
    leftHeight += height;
  } else {
    rightHeight += height;
  }
  if (leftHeight <= rightHeight) {
    state.leftGoodsList.push(state.pagination.list[count]);
  } else {
    state.rightGoodsList.push(state.pagination.list[count]);
  }
  count++;
}

// 清空列表
function emptyList() {
  resetPagination(state.pagination);
  state.leftGoodsList = [];
  state.rightGoodsList = [];
  count = 0;
  leftHeight = 0;
  rightHeight = 0;
}

// 搜索
function onSearch(e) {
  state.keyword = e;
  emptyList();
  getList(state.currentSort, state.currentOrder);
}

// 点击
function onTabsChange(e) {
  // 如果点击的是【综合推荐】，则直接展开或者收起筛选项
  if (state.tabList[e.index].list) {
    state.currentTab = e.index;
    state.showFilter = !state.showFilter;
    return;
  }
  state.showFilter = false;

  // 如果点击的是【销量】或者【新品优先】，则直接切换 tab
  if (e.index === state.currentTab) {
    return;
  }

  state.currentTab = e.index;
  state.currentSort = e.sort;
  state.currentOrder = e.order;
  emptyList();
  getList(e.sort, e.order);
}

// 点击 tab 的 list 筛选项
const onFilterItem = (val) => {
  // 如果点击的是当前的筛选项，则直接收起筛选项，不要加载数据
  // 这里选择 tabList[0] 的原因，是目前只有它有 list
  if (
    state.currentSort === state.tabList[0].list[val].sort &&
    state.currentOrder === state.tabList[0].list[val].order
  ) {
    state.showFilter = false;
    return;
  }
  state.showFilter = false;

  // 设置筛选条件
  state.curFilter = val;
  state.tabList[0].name = state.tabList[0].list[val].label;
  state.currentSort = state.tabList[0].list[val].sort;
  state.currentOrder = state.tabList[0].list[val].order;
  // 清空 + 加载数据
  emptyList();
  getList();
};

async function getList() {
  state.loadStatus = 'loading';
  const { code, data } = await SpuApi.getSpuPage({
    pageNo: state.pagination.pageNo,
    pageSize: state.pagination.pageSize,
    sortField: state.currentSort,
    sortAsc: state.currentOrder,
    categoryId: state.categoryId,
    keyword: state.keyword,
  });
  if (code !== 0) {
    return;
  }
  state.pagination.list = _.concat(state.pagination.list, data.list);
  state.pagination.total = data.total;
  state.loadStatus = state.pagination.list.length < state.pagination.total ? 'more' : 'noMore';
  mountMasonry();
}

// 加载更多
function loadMore() {
  if (state.loadStatus === 'noMore') {
    return;
  }
  state.pagination.pageNo++;
  getList(state.currentSort, state.currentOrder);
}

onLoad((options) => {
  state.categoryId = options.categoryId;
  state.keyword = options.keyword;
  getList(state.currentSort, state.currentOrder);
});

// 上拉加载更多
onReachBottom(() => {
  loadMore();
});
</script>

<style lang="scss" scoped>
.goods-list-box {
  width: 50%;
  box-sizing: border-box;

  .left-list {
    margin-right: 10rpx;
    margin-bottom: 20rpx;
  }

  .right-list {
    margin-left: 10rpx;
    margin-bottom: 20rpx;
  }
}

.goods-box {
  &:nth-last-of-type(1) {
    margin-bottom: 0 !important;
  }

  &:nth-child(2n) {
    margin-right: 0;
  }
}

.list-icon {
  width: 80rpx;

  .sicon-goods-card {
    font-size: 40rpx;
  }

  .sicon-goods-list {
    font-size: 40rpx;
  }
}

.goods-card {
  margin-left: 20rpx;
}

.list-filter-tabs {
  background-color: #fff;
}

.filter-list-box {
  padding: 28rpx 52rpx;

  .filter-item {
    font-size: 28rpx;
    font-weight: 500;
    color: #333333;
    line-height: normal;
    margin-bottom: 24rpx;

    &:nth-last-child(1) {
      margin-bottom: 0;
    }
  }

  .filter-item-active {
    color: var(--ui-BG-Main);
  }
}

.tab-item {
  height: 50px;
  position: relative;
  z-index: 11;

  .tab-title {
    font-size: 30rpx;
  }

  .cur-tab-title {
    font-weight: $font-weight-bold;
  }

  .tab-line {
    width: 60rpx;
    height: 6rpx;
    border-radius: 6rpx;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: 10rpx;
    background-color: var(--ui-BG-Main);
    z-index: 12;
  }
}
</style>